Apparatus for radially contracting and elongating metal cylinders



F. C. LANGENB Feb. 10, 1931. G

' APPARATUS FOR RADIALLY TR NG AND ELONGATING METAL CYLIN 1 Filed July 21. 1930 .m mwra/e lr/r/vsssr I v 1 Ewe/22x 2236;

Patented Feb. 10, 1931 UNITED STATES rnnnnmcx c. LANGENBERG,

UNITED STATES PIPE AND CORPORATION OF NEW JERSEY or EDGEWATER' PARK, rounnmz conrm, or,

BURLINGTON,

ursnnrvs ron RADIALLY comaacrma nnonea'rme mar. mmnnns Application filed Ju1y'21,

In my pending application, filed December 29, 1928, Serial -Number 329,208, 'I have described and illustrated a method for radially contracting and simultaneously elongating metal cylinders and apparatus adapted for practicing the method and in m Patent. No. 1,753,747, dated April 8, 1930, specifically describe and claim the application of my method to the manufacture of metal molds adapted for the centrifugal casting of pipe. Inmy saidformer application an patent I have illustrated a construction in which a packing is inserted between .the cylinder under treatment and the wall of the container, as a result of which construction the hydraulic pressure a plied to eflect the radial contraction of t e c linder under, treatment. is not applied to t e portion of the cylinder lying outside of the packing and the object of my present invent-ion is to provide an improved construction whereby the hydraulic pressure can be applied to the end or ends of the cylinder under treatment so that said end or ends can be readily contracted as well as the intermediate portions of the cylinder; essentially my invention consists in providing a sleeve or follower fitting over the mandrel on which the cylinder is to be compressed and abutting against the end of the cylinder which is free to expand longitudinally under treatment, said sleeve or follower being pro vided with a' slightly enlarged head and fitting in a packing formed between its bodZ portion and the walls of the container.

suitable packing is also required and provided at the contact line between the end of the follower and the end of the cylinder so as to exclude the pressure fluid from passing through the joint to the inside of the cylinder under treatment. Other features of my improved construction will be best understood as described in connection with the drawings, which illustrate apparatus especiall adapted for radially contracting and long tudinally elongating steel molds adapted for the centrifugal manufacture of pipes, said apparatus embodying my present improvements.

The drawing shows, in Fig. 1, a vertical sectional elevation through the apparatus taken 1930. Serial No. 469,539.

through the center line thereof with a steel mold lank in the position to be operated. upon and in 'Fi s. 2 and 3 a detailed construction of arts 0 the apparatus. A in icates the container, which is best located in a vertical osition. Thecontainer is internally of cylindrical form'with anenlargement at the head forming a shoulder, indicated at A. A A indicate bolt holes formed in the top of the container. A indicatesthe port through which water or other fluid under heavy pressure is introduced into the container. A indicates bolt hol es located in the lower end of the container. Afindica'tes a portion of the cylindrical wall of the container against which the packin at theflower end of the container rests. I? indicates a plate of hard steel covering the top ofthe container and covered in turn by the heavy head 0, which is made sufiiciently massive and strong to resist the pressure when the pressure fluid is introducedinto the container. This plate is formed with bolt holes as indicated at C which register with 'the threaded bolt holes A in the headof the container. D, D indicate the bolts which secure the head to the container. E is a heavy annulus resting on the head C and formed with flanges indicated at E through which pass heavy tie rods H, secured at their lower ends to a bottom plate F, which is also secured to the bottom of the container by bolts indicated at G. This plate extends slightly inside of the cylindrical bore of the container. 1 indicates an annular spacing iece which when the apparatus is assemble rests through an intervening spacing piece I against the plate B.

hese spacing pieces are provided as shown with threaded perforations J for the insertion of eyebolts used in handling the parts.

K is the mandrel upon which the cylinder under treatment is contracted andwhich ives final form to the inside of the c'ontracte cylinder; in the case illustrated this mandrel is formed with a threaded extension K at its top and with a bottom extension of smaller diameter indicated at K, the lower end of which is threaded. In the case illustrated the upper end of the mandrel upon which the bell portion of the mold is NEW JERSEY, A.

as shown, formed to make a neat fit with the portion of the mold. blank which in the'finished mold forms a seat for the core used in casting bell ended pipes. The portion K is. 'shown .asprovided with threaded perforations indicated at J for the reception of eyebolts used in handlingthispart ofthe apparatus. I indicates a nut screwingon the;

threaded end of the bottom extension of the mandrel. M indicates a cylindrical support resting at bottom on the ledge A of the container and supporting at its top packi'rig'in dlcated at N, upon. the top of which rests a ring 0, which fits against the outer flange of the mold blank and upon. which the mold blank is supported, F indicates a metallic ring screwing on the threaded end of the mold blank and fitting againstthe flange of the blank and against the annular spacing pieceI. Q is an annular ring the lower end of which rests u on theprojecting edge of the plate F and t e upper edge of which supports a packing made up as shown of a fibre annulus R and aleather packing S, resting on the fibre. T indicates a differentialsleeve or follower, the lower portionof which fits over the extension K of the, mandrel and which should have only sufficient clearance to enable it to be contracted upon the mandrel without exceeding the elastic limit of the material of which it is composed. The outer portion of this portion of the sleeve fits against the packing indicated at R, S. The upper portion of the differential sleeve is enlarged as indicated at T to fit overthe lower end of'the mandrel proper and again should have only such clearance as would enable it to be contracted on the mandrel without exceeding the elastic limit of its material. As the drawing shows, the differential sleeve is provided with an extension T forming a fairly close fit with the inside of the contain er, through which are formed channels indi cated at T The lower face of the exten sion indicated at T? is as shown of greater diameter and area than the upper face T so that when pressure is admitted to the container it will exert an upward force on the differential sleeve. U indicates the mold blank'as it is located in the apparatus prior to the admission of pressure fluid to the container to radially contract it. U indicates the lower end of the mold, which-should be finished off with a smooth surface perpen-- U indicates the bell portion of the mold, formed dicular to the axial line of the mandrel.

with an outwardly extending flange U and an upwardly extending externally threaded extension U; U indicates-the core seat. V

is a soft metal ring located at the contact edge The.

of the difierential sleeve and the lower end of the mold blank and overlaid by a layer of rubber or the like V which extends over the lower end of the mold and the upper end of the differential follower, as shown.

Preparatory to operation the mold is assembled in the apparatus as shown in thedrawings and pressure fluid is admitted to the container through the port A When the pressure has reached about a thousand pounds to the square inch the nut L which has been screwed up on the threaded extension of the mandrel so as to hold the differential sleeve tight against the end of the blank is removed and the pressure thereafter raised to a sufficient amount to effect the radial contraction and simultaneous elongation of the blank, which elongation of course in such an assembly as that described results in a downward pr'ojection of the lower end of the blank carrying with it the difi'erential follower which is held against the'endof the blank with a pressure determined by the effective increase of the diameter of the'head of the follower over its lower portion. This upward thrust of the follower involves the use of greater pressure in the container to effect the contraction of the blank than would be necessary if no such upward thrust was exerted against the blank but this is compensated for operating to thrust the differential follower downward instead of upward against the end of the blank. It is therefore advisable, as shown, that the contacting end of the follower should be less in diameter than the diameter of the blankagainst which it rests andso proportioned that even when contracted the end of the blank will not extend within the periphery of the head of the follower.

It is advisable that a lubricant such as white lead should be used to coat the mandrel so as to dimnish as much as possible the fric tion due to the downward extension of the blank after it is contracted ontheinandrel and the friction due to the cont'raction of the the clearance between the differential follower and the portions of the mandrel which it'overlies should not exceed the amount to which the sleeve can he contracted on the mandrel without exceeding the elastic limit of the material of which it is constructed. In this way the differential sleeve after the withdrawal of pressure resumes its origlnalform,

permitting its ready withdrawal and its reuse on other blanks.

The composite packing used to close the joint between the head of the dillcrential follower and the blank and made up as described of a soft metal ring overlaid by a rubber-like cover has been found very etlectiveto prevent the entrance of pressure to the inside of the blank under treatment.

\Vhile I have illustrated the apparatus as constructed for the treatment of blanks used in the. formation of pipe molds, my invention is obviously applicable to the similar treatment of all substantially cylindrical bodies which it is desired to similarly contract and elongate and of course in the treatment of purely cylindrical bodies such as pipes the differential sleeve construction described can be used at both ends of the container, though equally of course it is obvious that all that is necessary is that one end of such a pipe should be in contact with the differential sleeve and the other firmly held in or on the head of the container,

Having now described my invention, what I claim as new and desire to secure by Letters atent,'is:

1. Apparatus for radially contracting and simultaneously elongating hollow metal bod ies of a substantially cylindrical shape, comprising a container for fluid under pressure having a port for the introduction of high pressure fluid thereto, a mandrel for limiting the radial contraction of the hollow cylindrical body, a hollow cylindrical follower adapted to give passage to the mandrel and having an enlarged head adapted to abut against the end of the cylindrical body under treatment, packing located between the follower and the container and packing adapted to close the joint between the follower head and the end of the cylindrical body 2. Apparatus as called for in claim 1 provided with means for temporarily clamping the follower against the end of the cylinder under treatment.

3. Apparatus as called for which the internal diameter of the follower is only so much greater than that of the mandrel as will permit the follower to be radially contracted upon the mandrel without exceeding the'elastic limit of its component material and imparting a permanent contraction to the follower.

4. Apparatus as called for in claim 1 in which the packing at the joint formed between the head of the follower and the end of the cylinder under treatment comprises a ring of plastic metal.

5. Apparatus as called for in claim 1 in which the packing at the joint formed between the head of the follower and the end of the cylinder under treatment comprises a ring of plastic metal and a layer of rubberlike material overlapping the metal ring.

in claim 1 in.

6. Apparatus as called for in claim 1 in which the mandrel is provided with an extension of smaller diameter and the follower is shaped to form a loose fit with the extension and with the end portion of the mandrel proper.

7. Apparatus as called for in claim 1 in which the follower is provided with centering means operative to maintain it approximately centered in the container without interfering with its longitudinal motion therein.

8. Apparatus as called for in claim 1 in which the container is secured in vertical position, the mandrel located in the container is formed with an extension at its lower end of less diameter than its body portion and the follower is located at the lower end of the container and formed to form a loose fit with the mandrel extension and the end portion of the body of the mandrel.

FREDERICK C. LAN GENBERG. 

